NEW ORLEANS - The Baltimore Ravens blew almost all of a 22-point, second-half lead Sunday night, but they stopped a last-ditch San Francisco drive at the 5-yard line and defeated the 49ers 34-31 to win the Super Bowl behind three touchdown passes from quarterback Joe Flacco.

The victory in the matchup of coaching brothers - Baltimore's John Harbaugh and San Francisco's Jim Harbaugh - was not accomplished without considerable angst by the Ravens.

Flacco, the game's MVP who completed 22 of 33 passes for 287 yards, threw all of his touchdown passes in the first half as the Ravens threatened to turn the game into a rout. He tied a single-year postseason record set by the 49ers' legend, Joe Montana, by throwing 11 touchdown passes without an interception.

Until the game was stopped for 34 minutes due to a power failure early in the third quarter, the Ravens were winning easily.

They led 28-6 thanks to Flacco's first-half work and a 108-yard return of the second-half kickoff by Jacoby Jones, the longest play in Super Bowl history.

However, the combination of a long halftime show, the power failure, Jones' kickoff return and a San Francisco offensive drive meant the Ravens' offense was off the field for 84 consecutive real-time minutes. After play resumed, Baltimore didn't look like the same team it was earlier.

Baltimore went cold while the 71,024 fans in the Superdome went warm due to the lack of air conditioning with no power available.

The stadium still had partial lighting over the field during the delay, but not enough power to play the game or cool the building.

The Ravens couldn't move the ball on their first post-delay possession, then fumbled it away on their second before finally starting a promising drive near the end of the third period.

After play resumed, the 49ers drove 80 yards in seven plays, scoring on a 31-yard pass from Colin Kaepernick to Michael Crabtree. Crabtree caught the ball at the 10-yard line, bounced off safety Bernard Pollard and ran into the end zone.

A Baltimore three-and-out followed the kickoff, the third-down play a blindside sack of Flacco by linebacker Ahmad Brooks, who came in untouched.

After a short punt was returned 32 yards by Ted Ginn, the 49ers covered 20 yards in two plays for their second touchdown in less than 2 1/2 minutes. Kaepernick threw 14 yards to tight end Vernon Davis, and then Frank Gore ran in on a misdirection play from the 6-yard line.

Later in the quarter, Ravens running back Ray Rice was stripped of the ball after a short completion by cornerback Tarell Brown, who also recovered, making it possible for Akers to kick a second try, 34-yard field goal. The Ravens were penalized for running into him after he missed a 39-yard attempt moments earlier.

That sliced San Francisco's deficit to 28-23. After Baltimore got a 19-yard Justin Tucker field goal early in the fourth quarter, the 49ers struck quickly for another touchdown. Kaepernick scored on a 15-yard scramble after a 32-yard pass to Randy Moss and a 21-yard run by Gore. However, Kaepernick's pass attempt for a two-point conversion missed, leaving the Ravens with a 31-29 lead.

Tucker added a 38-yard field goal with 4:23 to go.

The 49ers then started a drive from their own 20-yard line that eventually gave them a first down at the Baltimore 7 with just over two minutes remaining.